Alkyl phosphites, preparation

First synthesis of aji organo-P comp iund by J. L. Lassaigne who made alkyl phosphites from H P04 + ROH. T. Graham (who later became the Hrst President of the Chemical Society) classiHed phosphates as ortho, pyro or meta, following J. J. Berzelius s preparation of pyrophosphoric acid by heat. 

Alkylperoxy hydridosilane, preparation, 783 Alkyl phosphites, ozone adducts, 732 Alkyl sodium alkyl peroxide,... 

Diazothioxanthene is the usual precursor for the thioxanthylidene carbene, which can be shown to have a nucleophilic character. It adds to fumaric or maleic esters to form cyclopropyl compounds, but does not react with cyclohexene (78JOC3303). Reaction with alkyl phosphites is a very useful means of preparing the phosphonate derivatives (72JIC985). 

Alkyl phosphite complexes can be prepared by alcoholysis of chlorophosphine complexes (equation 47).274>332... 

Perchlorofulvalene is a highly reactive chlorocarbon which undergoes a variety of reactions, including dimerization and addition reactions, especially with nucleophiles. It has a unique structure4 which reflects a compromise between steric hindrance and conjugation. The method of preparation exemplifies the use of the mild dehalogenating properties of alkyl phosphites. 

The possibility that R-0 fission may occur in advance of attack by halide ion has been demonstrated in the reactions of dineopentyl phenyl phosphite or neopentyl diphenyl phosphite with alkyl halides. In these cases the Michaelis-Arbuzov intermediates cannot be isolated but the neopentyl halides which are formed are contaminated with varying amounts of rearrangement product (t-pentyl halide) (Table IV). These results may explain the formation of mixtures of isomeric halides (9,10,11) in certain applications of Rydon s method for alkyl halide preparation (12). S i fission of the R-0 bond appears to be encouraged by the electron-attracting effect of phenoxy-substituents (Figure 3). 

Butyl phosphate has been prepared by the action of phosphorus oxychloride upon -butyl alcohol, aluminum butoxide, or sodium butoxide. The above procedure is similar to one that has been used for the preparation of alkyl phosphites. ... 

Diphenyl phosphorochloridite hydrolyzes slowly in air and more rapidly in water, but it is less reactive toward nucleophilic reagents than most chlorine derivatives of phosphorus(III). The reaction with alcohols in the presence of a tertiary base is used to prepare diphenyl alkyl phosphites. Addition of sulfur occur.s on reaction with thiophosphoryl chloride. 

C10H21, Ph) " and phosphonoacetates containing unsaturated substituents at either the phosphorus atom or the carboxy group. - The reaction can be used to prepare any dialkyl 1-(alkoxycarbo-nyl)methylphosphonates from chloro- " - or bromoacetates in fair to excellent yields (35-99%, Scheme 8.6, Table 8.1). Although chloro- or bromoacetates may be employed for the preparation of l-(ethoxycarbonyl)methylphosphonates, the bromo derivatives, which give the better yields, are often preferred. The use of sensitive /r/Y(trimethylsilyl) phosphite, - Z /5(trimethylsilyl) alkyl phosphite, and trimethylsilyl bromoacetates has been reported. 

Phosphorylated derivatives are also available. Cellulose pulp or linters can react with phosphoric acid in a urea melt or with a mixture of phosphoric acid and phosphorus pentoxide in an alcoholic medium to prepare cellulose phosphate. Cellulose phosphites and phosphonates are produced via transesterification with alkyl phosphites. All these compounds have fire-retarding properties and ion-exchange properties and cellulose phosphate is used in textile and paper manufacture, as well as in the treatment of kidney stones. 

Arylphosphonates (182) are prepared in good yield from an arene and either a tri- or di-alkyl phosphite, using anionic or a chemical oxidant respectively. The scope of this process has been... 

Formation of esters of inorganic acids (Section 15.9) Alkyl nitrates, dialkyl sulfates, trialkyl phosphites, and trialkyl phosphates are examples of alkyl esters of inorganic acids. In some cases, these compounds are prepared by the direct reaction of an alcohol and the inorganic acid. 

Preparation of (Me0)2P-0-R ROH, (MeO)3P, CBr4, Pyr, 70-98% yield. The alkyl dimethyl phosphite may then be oxidized to the corresponding phosphate by aq. iodine, t-butyl hydroperoxide, or peracid. 

Most common is the preparation of alkyl phosphonic acid esters (phospho-nates) 4 (Z,Z = OR) from phosphorous acid esters (phosphites) 1 (Z,Z = OR). The preparation of phosphinic acid esters (Z = R, Z = OR) from phosphonous acid esters, as well as phosphine oxides (Z,Z = R) from phosphinous acid esters is also possible. 

In the alkyl chain hydroxy groups or side chains may be present. The reaction is somewhat different when acyl halides are used. Hydroxymethanediphosphonic acid is prepared by reacting phosgene with an alkali metal, dialkyl phosphite. The reaction is rapid and exothermic. The temperature is controlled between 10 and 20°C. After hydrolysis with HC1, hydroxymethanediphosphonic acid is recovered [91,92]. 

Sulfonic esters are most frequently prepared by treatment of the corresponding halides with alcohols in the presence of a base. The method is much used for the conversion of alcohols to tosylates, brosylates, and similar sulfonic esters. Both R and R may be alkyl or aryl. The base is often pyridine, which functions as a nucleophilic catalyst, as in the similar alcoholysis of carboxylic acyl halides (10-21). Primary alcohols react the most rapidly, and it is often possible to sulfonate selectively a primary OH group in a molecule that also contains secondary or tertiary OH groups. The reaction with sulfonamides has been much less frequently used and is limited to N,N-disubstituted sulfonamides that is, R" may not be hydrogen. However, within these limits it is a useful reaction. The nucleophile in this case is actually R 0 . However, R" may be hydrogen (as well as alkyl) if the nucleophile is a phenol, so that the product is RS020Ar. Acidic catalysts are used in this case. Sulfonic acids have been converted directly to sulfonates by treatment with triethyl or trimethyl orthoformate HC(OR)3, without catalyst or solvent and with a trialkyl phosphite P(OR)3. ... 

An allylic sulfenate, like 199, is known to be in equilibrium with allylic sulfoxide, like 196, although its concentration is usually low . Various allylic sulfoxides can be prepared by treatment of allylic alcohols with arenesulfenyl chlorides . Evans and coworkers prepared various allylic alcohols by treating the corresponding allylic sulfoxides with trimethyl phosphite. For example, the carbanion from a cycloalkenyl sulfoxide 201 was readily alkylated at the a-position by treatment with alkyl halide. The resulting alkylated derivative 202 was then treated with trimethyl phosphite and 3-substituted cycloalkenol was obtained. Alkylation of acyclic allylic sulfoxide 204 gave... 

Preparation of 2,3-dioleoyloxypropylphosphonic acid — Reaction of an alkyl halide with a silyl phosphite ester... 

Preparation of 5-(3-benzoylpropionyl)-3-deoxy-3-diisopropoxyphosphinylmethyl-l,2-di-0-acetyl-D-ribofuranose — Reaction of an alkyl bromide in a carbohydrate series with triisopropyl phosphite... 

Preparation of di-n-butyl N,N-diethylcarbamoylmethylphosphonate — Phase transfer-catalyzed reaction of a dialkyl phosphite with an alkyl chloride... 

Several methods for the preparation of the parent compound in this system, tris(trimethylsilyl)phosphite, have been reported.114 118 The application of this and related reagents in reaction with alkyl halides has been reported and used for the preparation of a variety of phosphonic acid analogues of phospholipids.114119-124 Interestingly, alkyl chlorides appear to be more reactive with the silyl reagents than do alkyl iodides, a reversal of the normally observed trend with alkyl esters of the phosphorus acids. (The particular use of silyl phosphorus reagents for the synthesis of biologically significant compounds has... 

Hudson, H.R., Rees, R.G., and Weekes, J.E., Preparation, structure, and nuclear magnetic resonance spectroscopy of triphenyl and trineopentyl phosphite alkyl halide adducts, /. Chem. Soc., Perkin I, 982, 1974. 

Indole, sodium salt, preparation of, 54, 60 Indole, 1-benzyl, 54, 50, 58 Indoles, iV-alkyl-, 54, 58, 60 Iodides, from alcohols, methyl iodide, and triphenyl phosphite, 51, 47 ... 

The carbanions take up 02 and these take up protons to give hydroperoxides in good yields. But because they are explosive in nature, they are not usually isolated and on reduction with sodium sulphite on trialkyl phosphite give alcohols. Alcohols can also be prepared via hydroperoxy molybdenum complexes and alkyl boranes. These reactions are summarized as follows ... 

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